1. Field of the Invention
This invention relates generally to a method and apparatus for the generation of chlorine gas for supply to a body of water, such as a swimming pool, and more particularly to a system including a novel arrangement of an electrolytic cell gas generator and a system for feeding the gases into a flowing stream of water diverted from the main body of water.
2. The Prior Art
The generation of chlorine and its introduction to a water reservoir such as a swimming pool, a cooling tower and the like is the subject of various patents, including U.S. Pat. Nos. 3,351,542 to Oldershaw, 3,669,867 to Kirkham, 2,887,444 to Lindstaedt, and 3,223,242 to Murray. However, these patents disclose generally complicated chlorine generation systems such as the one shown in the Murray patent. Oldershaw includes a system which includes a conceivably dangerous electrolytic solution, such as hydrochloric acid, whereas Lindstaedt requires the addition of sodium chloride to the stream of water which flows directly into the pool. Obviously, the Lindstaedt arrangement and others like it where sodium chloride is injected into a body of water which is to be used by a human is highly undesirable. Kirkham includes a cooling element for one of its electrode compartments within the electrolytic cell, likewise making that structure unnecessarily complicated.
Other known patents relating to electrolytic cells include U.S. Pat. Nos. 3,117,066 and 3,291,708 to Juda, 4,035,254 to Gritzner, 4,010,085 to Carlin and 3,975,284 to Lambert.
U.S. Pat. No. 3,361,663 to Murray even discloses a system for injecting a sanitizing gas into a flowing stream of water for use in a swimming pool. However, the present invention distinguishes significantly from the Murray system to provide the advantages which will be more fully explained and appreciated in further portions of this disclosure.
Additionally, ion permeable membranes used in previous chlorine generation systems have ranged from, for example, asbestos diaphragms to perfluorosulfonic acid membranes such as described in U.S. Pat. No. 3,909,378 to Walmsley. The perfluorosulfonic acid membranes as disclosed in the latter patent have also been described in conjunction with a chlorine generator system in such publications as du Pont Magazine, May-June, 1973, pp. 22-25 and in a paper entitled "Perfluoronated Ion Exchange Membranes" by Grot, Munn and Walmsley, presented to the 141ST National Meeting of the Electro-Chemical Society, Houston, Tex., May 7-11, 1972. Additional patents relating to perfluorosolfonic acid membranes used in electrolysis reactions include U.S. Pat. Nos. 3,793,163 to Dotson, 3,775,272 to Danna, and 4,010,085 to Carlin. Another known patent relating to diaphragms for electrolytic cells is U.S. Pat. No. 3,853,720 to Korach.
All the referenced patents and articles referred to above are incorporated herein by reference for all purposes.
Various problems are associated with the prior art type generators. For example, the Lindstaedt patent discloses a system where sodium chloride is injected into the main body of water, and is undesirable as previously discussed. The disclosure of Murray, U.S. Pat. No. 3,361,663, for example, accumulates the gases generated in the electrolytic cell and conveys them by one single line for injection into the flowing stream of water, and potentially creates a hazard of mixing two incompatible gases through the single conduit conveying line. Moreover, the Murray system does not include any provision for sensing the pressure of water flow from the pool filtration cycle, such that gases would continue to be generated even if water pressure were lost from that filtration cycle.